Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) causing adverse effects on both humans and animals. Immune system is an important target organ for many environmental contaminants. Macrophages constitute an important component of the immune system of humans and animals, in fact, they are responsible for triggering innate immune responses and host defense. The aim of the current study was to assess the immunomodulatory effects of certain non dioxin like PCBs (PCB 138; PCB 153 and PCB 180) using porcine macrophage 3D4/31 cell line. We evaluated not only the effects induced by the individual congeners but also those deriving from mixtures of more contaminants, in consideration of the fact that co-contamination of the same substrate is common in natural conditions and the effects of simultaneous exposure to multiple contaminants are still little investigated. The results of the current study showed that ndl-PCBs reduced significantly cell viability only at the highest concentration (50 µM); such effect was not linked to apoptosis induction or cell cycle arrest. The contemporary presence of more than one contaminant (differently combined) did not induce any enhancement of effects on 3D4/31 cell line
